1. Field of the Invention
This invention relates to a game processing method, game device, image processing device, image processing method and recording medium, and more particularly, to game processing whereby objects, such as cars, or the like, are moved about on a monitor in response to operations by players, as in a driving (car race) game.
2. Description of the Related Art
With the progress of computer graphics technology in recent years, image processing devices providing a variety of images have been proposed. Some of these are used in so-called video game devices, and provide race games, shooting games, simulation games, action games, or the like.
In game devices of these kinds, whether they be for domestic or commercial use, devices capable of displaying clearer and more realistic images are in demand. Game devices are generally provided with: a game main unit containing an inbuilt computer device for implementing pre-recorded game programs, operating devices for supplying the computer device with operating signals instructing objects represented in the game to move, a display for displaying images relating to the development of the game in accordance with the game program implemented by the computer device, and a sound device for generating sounds relating to the development of the game.
In recent years, in order to create impressive screen images of even higher quality, video images created by defining image data in a virtual three-dimensional coordinate space, positioning objects (characters), a background, and the like, in this space, and viewing this from a prescribed viewpoint, have come to be displayed in video game devices.
(Prior Art Example 1)
One type of a game device constituted in this way is a device for playing driving games (car race games). In this type of game device, it is possible to play a rally-type game where a plurality of players take part and compete for position.
(Prior Art Example 2)
Furthermore, in driving games, it is sought to create as realistic as possible a simulation of car movements, and this point is important to the players' enjoyment of the game.
Conventionally, simulations of this kind use a single-point model in place of the car at one material point, such as the car's center of gravity. The state of contact (also called impact or collision) between the car (tires) and the ground is determined by this one point alone, and a simplified simulation is produced without making any calculation for suspension or the like. Therefore, the game only depicts a monotonous movement of the car under specific conditions, and there is no movement of the car in the pitch, roll or yaw directions, or alternatively, the car is caused to drift when the steering angle is above a certain value.
Simulations based on single-point models of this kind involve simple processing and any car movement desired by the manufacturer can easily be reproduced, but there remains an unnatural feeling about the simulated movement of the car, meaning that the game lacks realism and the game device has a low added value.
Therefore, rather than taking the car as a single material point, game machines have been devised which are capable of implementing more complete simulations in real time, wherein the four tires are in contact with the road surface and each tire respectively receives a force from the road surface, these forces act upon the car through the suspension, and the movement of the car is determined accordingly.
(Problem 1)
As described previously, in a conventional communicative race game where a plurality of people can play, when one person inserts a coin, the message "Waiting for player" is displayed on the other screen, and that person waits while other users of the game device get ready. During this time, the first player cannot do anything (or even if he or she can, it will merely be something like selecting the course,) and he or she must wait until a count-down is completed. Furthermore, since in most games the course selection is based on a majority decision, it is often the case that players are not able to use the course they want when skilled players are mixed with beginners.
Furthermore, once the game has started, the race leader (the person in first position) is able to extend the race. If the race leader passes through a check point within a prescribed period of time, then even if the other players have not reached the check point, for example, all of them will have their game time extended. Whilst this is advantageous in that all the players can enjoy the game to the very end, from the viewpoint of competitive racing where the aim is to beat the other players, it leaves a feeling of dissatisfaction. Moreover, as regards the conditions for the end of the game, the game is stopped compulsorily when the race leader's time reaches zero, or when the race leader reaches the end.
Furthermore, conventionally, in order to ensure competition between skilled players and novices on the race screen, compensating factors are applied (for example, the cars of lower placed players are speeded up, or the timing of restarts after crashing is changed). However, skilled players may be unhappy with this, since from their point of view they are unable to create a distinction which corresponds to their skill level, and many people have complained that in the end driving becomes difficult and they get no satisfaction even if they do win, because even novices can drive fast.
(Problem 2)
If it is seriously sought to simulate the movements of an object in a car race game, then it is necessary for movement to be applied to the car in directions other than the one selected by the steering wheel or the direction in which the car is facing, according to the standard laws of dynamics. For example, in creating a proper simulation it is desirable to apply movements such as spinning, tail slides and four-wheel drift to the car.
In this case, when simulating the movement of the whole car, it may be seen as desirable to compute the forces and the like applied to each of the four wheels of the vehicle, as in an actual car, but this inevitably increases the computing load on the CPU and if this computing process is conducted properly, then other image processing will not be carried out adequately. Of course, it is also possible to eliminate problems of this kind by using a CPU with increased computing power, but in this case, not only are manufacturing costs raised, but the time required for computer processing also increases. In addition, there is the problem of the work required to create a program for calculating the forces and the like applied to each of the four car wheels.
In an image processing device, particularly a game device, which is required to respond swiftly to operations by the player or operator, it is inconvenient if a long time is required for calculation, and ultimately, this will detract from the appeal and interest of the game device for the player or operator.
Furthermore, conventionally, in game devices of this kind, consideration has not been given to conducting this image processing rapidly and reliably after it is judged that there has been a collision between two cars, which are the objects of the game.